Previously untreated, asymptomatic, single-rooted maxillary anterior teeth with periapical lesions <5 mm, no fractures, resorption, calcification, or recent antibiotic use will performed two-visit root canal treatment. Initial radiographs will be taken. After rubber-dam isolation, working length will be determined; canals prepared step-back to size #40 with sodium hypochlorite (NaOCl) irrigation, rinsed and dried. Between appointments, Metapaste or Bio-C TEMP will be placed as intracanal medicament for 7-10 days. At the second appointment medicaments removed, final irrigation performed and root canals obturated and restored. Pain scores recorded at 6h,12h,1d,2d,3d,4d,5d,6d,7d ; follow-ups at 6, 12 and 24 months.

Within the scope of the project, two-visit root canal treatment will be performed on previously untreated, asymptomatic, single-rooted, single-canaled maxillary anterior teeth that have periapical lesions smaller than 5 mm on radiographs, no fractures or cracks, no internal or external resorption, no canal calcification, and no antibiotic use within the last week.

At the start of treatment, an initialradiograph will be taken of the tooth using a parallel film holder and archived. After rubber dam isolation, an access cavity will be prepared (all previous restorations will be removed if present). Working length will be determined by an apex locator. Root canal preparation will be performed using the step-back technique, with apical enlargement to at least size #40. Continuous irrigation with 2.5% NaOCl will be performed between each file. After instrumentation, the root canals will be rinsed with distilled water and dried with paper points.

Between appointments, to achieve additional disinfection of the root canals, Metapaste containing Ca(OH)₂ intracanal medicament (Meta Biomed Co., Ltd., Chungcheongbuk-do, Korea) and the bioceramic-based intracanal medicament Bio-C TEMP (Angelus, Paraná, Brazil) will be placed in the root canals according to the manufacturers' instructions. The intracanal distribution of the medicaments will be checked visually and radiographically, and the medicaments will be left in place for 7-10 days. Patients will be instructed on how to record their pain scores on the NRS scale and will be provided with contact information in case of any swelling or pain.

At the second appointment, after removal of the medicaments, a periapical radiograph will be taken for gutta-percha trial and verified according to the working length. In the final irrigation procedure, 5 mL of 17% ethylenediaminetetraacetic acid (EDTA), 5 mL of 2.5% NaOCl, distilled water and 2% chlorhexidine will be used respectively. After drying the root canals with paper points, they will be obturated with gutta-percha and a resin-based sealer using the cold lateral compaction technique, and the access cavities will be restored with composite resin. A final radiograph will be taken using the parallel technique with a parallel film holder.

Patients will again be given the NRS form and asked to return the completed forms after 7 days. Clinical follow-ups will be performed at the 6th, 12th, and 24th months, and follow-up radiographs will be taken using a parallel film holder. Changes in the size of the periapical lesions compared to baseline will be evaluated.

Inclusion Criteria:

• with a non-contributory medical history, mature maxillary incisor teeth with periapical lesions, diagnosed as asymptomatic apical periodontitis

Exclusion Criteria:

• clinical symptoms, drainage, more than 5 mm loss of periodontal attachment, Teeth with periapical lesions larger than 5 mm previous endodontic treatment, non-restorable tooth patient with taken antibiotic or analgesics